Heart rate increases during physical activities. When the exercise stops, the heart needs a bit of rest to return to normal parameters, and it will not immediately return to normality, slower rate; age, gender, and physical conditions also influence the time period the heart needs to return to a normal beat per minutes (BPM).
The more intense the exercise, the more your heart rate will increase: taking note of your heart rate during your physical activities can help you monitor the intensity of your exercise.